Certificate of Analysis (CoA): what to include and how to format it
What a Certificate of Analysis should contain, how to format the results table, and how a CoA differs from a Certificate of Conformance, with a reusable structure for consistent, batch-specific CoAs.
A Certificate of Analysis (CoA) is a batch- or lot-specific document that reports the characteristics a product was tested for, the method and specification used, and the actual results obtained. Where a Certificate of Conformance asserts that requirements are met, a CoA shows the evidence. It is standard in chemicals, materials, pharmaceuticals, food, and any supply chain where a customer needs to verify measured properties before accepting a lot.
What belongs on a Certificate of Analysis
The heart of a CoA is a results table: for each characteristic, the specification limit, the test method, and the measured result. Around that core, the certificate carries the identification and sign-off that make it traceable.
| Characteristic | Specification | Method | Result |
|---|---|---|---|
| Assay / purity | ≥ 99.0% | HPLC | 99.6% |
| Moisture | ≤ 0.5% | Karl Fischer | 0.21% |
| Particle size (D50) | 40–60 µm | Laser diffraction | 52 µm |
| Appearance | White powder | Visual | Conforms |
Above the table, identify the material (name, grade, part number), the batch or lot number, the manufacturing or expiry dates where relevant, and the specification the results are judged against. Below it, include a conformance statement and an authorized signatory. In EN 10204 terms, a CoA populated with validated test results corresponds to a Type 3.1 inspection certificate.
Formatting results so they’re unambiguous
- State the specification limit and the result in the same units, side by side
- Name the test method for every characteristic, because a result without a method isn’t verifiable
- Show a clear pass/fail or “conforms” outcome, not just a number the reader has to judge
- Keep the row order and field names identical from batch to batch so results are comparable over time
The single most useful habit for CoAs is consistency across lots: same characteristics, same order, same names. It turns a stack of certificates into a dataset you can trend.
CoA vs CoC: which does your customer need?
If the customer needs the measured evidence, they want a CoA. If they need a traceable assertion of compliance without every number, a Certificate of Conformance is enough. Many quality agreements require both: a CoC as the shipment-level declaration and a CoA as the batch-level evidence. See the CoC vs CoA comparison for how the two fit together.
Keeping the CoA consistent lot to lot
Because a CoA repeats the same characteristics and layout while the results change every batch, it benefits enormously from a fixed template. Holding the specification limits, methods, and field names in a controlled structure, and filling only the results, removes the drift that creeps in when each certificate is a fresh copy of the last one. That is the same structured-data approach that keeps product data sheets consistent, applied to test results. DataSheets Pro gives you a structured starting point for a CoA; verifying the limits, methods and format against your own specification and customer requirements remains your responsibility.
Start from the templateCertificate of Analysis template: free & editable
Report a batch's test results against their specifications in a clean, branded CoA, then export a supplier-ready PDF, free to start.
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